1. Field of the Invention
The present invention relates to rotational angle detecting devices and in particular to rotational angle detecting devices that can detect the rotational angel in a non-contact manner. The present invention also relates to resin-molded products usable for the rotational angle detecting devices and methods of manufacturing such products.
2. Description of the Related Art
In general, a rotational angle detecting device includes a rotary section and a stationary section. A pair of permanent magnets are attached to the rotary section in positions opposing to each other with respect to the center of rotation. An angle sensor is disposed on the stationary section and can determine the rotational angle of the rotary section based on change of a magnetic field as the rotary section rotates. The magnetic field is generated between the permanent magnets. A connector is provided on the stationary section for electrically connecting the rotational angle detecting device to an external device.
For example, Japanese Laid-Open Patent Publication No. 2001-289610 discloses a rotational angle detecting device shown in FIGS. 17(A) and 17(B). With this rotational angle detecting device, a plurality of connecting terminals 102 (only one connecting terminal 102 is shown in the drawings) of an angle sensor 100 are connected to end portions 105t of conductors 105 (only one conductor 105 is shown in the drawings). Opposite end portions 105z of the conductors 105 are used as connector terminals.
After the connecting terminals 102 have been connected to the end portions 105t of the conductors 105, they are inserted into a first die (not shown) for molding a first resin-molded portion 106 at a connecting region between the connecting terminals 102 and the conductors 105. Therefore, the connecting terminals 102 and the conductors 105 are integrated together. Next, a stator core 107 made of iron covers the resin-molded portion 106 and the angle sensor 100 located outside of the first-resin molded portion 106. Subsequently, the resin-molded portion 106 and the angle sensor 100 covered with the stator core 107, and the conductors 105 are inserted into a second die for molding the stationary section by resin. Thereafter, the rotary section and the stationary section are positioned relative to each other, so that a predetermined positional relation between the magnets of the rotary section and the angle sensor can be achieved.
However, with this rotational angle detecting device, the first resin-molded portion 106 covers only the connecting region between the connecting terminals 102 and the end portions 105t of the conductors 105, and the angle sensor 100 is located outside of the first resin-molded portion 106. More specifically, portions of the connecting terminals 102 and the angle sensor 100 are positioned outside of the first resin-molded portion 106. Therefore, for example, if the angle sensor 100 has been displaced or moved by an external force applied to the connecting terminals 102, there is a possibility that the assembling operation of the stator core 107 becomes troublesome or may not be properly performed.
In another known rotational angle detecting device disclosed in Japanese Laid-Open Patent Publication No. 2005-91275, electrical connecting terminals are provided on the angle sensor and are connected to connector conductors via conductors provided on a printed circuit board. Capacitors for preventing generation of noises are connected to the connector terminals via corresponding conductors provided on the printed circuit board.
Because the electrical connecting terminals of the angle sensor are connected to the connector conductors via the conductors on the printed circuit board, the known rotational angle detecting device must have a large size as it requires the printed circuit board. In addition, because the capacitors for preventing generation of noises are connected to the printed circuit board, it is difficult to position the capacitors proximally to the angle sensor. Therefore, the noise removing effect cannot be fully exerted.